Common side effects of Suhagra 25 mg may include headache, dizziness, flushing, indigestion, nasal congestion, and changes in vision such as blurred vision or sensitivity to light. These side effects are usually mild and temporary, but if they persist or worsen, it's important to contact your healthcare provider. Rare but serious side effects may include priapism (prolonged erection), sudden hearing loss, and allergic reactions. Seek immediate medical attention if you experience any of these severe side effects.